Production of recombinant proteins suitable for use as therapeutics is typically an arduous and costly process. The expression system to be used to express a given protein is partially dependent upon the protein yield derived from each system. In considering a suitable method for antibody manufacture, for example, a variety of factors must be evaluated. These include antibody structure, the importance of carbohydrate, and expression, which includes yield and productivity, ease of purification and cost of goods. The yield greatly affects the cost of goods associated with any such process.
In general, recombinant expression technology in mammalian cell culture has been the principal means for the commercial production of therapeutic antibodies. Mammalian systems are beneficial for antibody production for several reasons including the glycosylation pattern on the expressed product. Often the recombinant proteins are produced in mammalian cell culture using either Chinese hamster ovary (CHO) or mouse myeloma (NS0) cell lines.
Generation of superior cell lines, for recombinant expression, which reach high cell densities and have great longevity in culture produce greater quantities of therapeutic protein per liter of cell culture grown. This leads to a greater efficiency and a lower cost of goods.